University of Cambridge Feb 22 2025 SARS-CoV-2 triggers the production of the antiviral protein IFN- γ , which is associated with fatigue, muscle ache and depression. New research shows that in Long COVID patients, IFN- y production persists until symptoms improve, highlighting a potential biomarker and a target for therapies.  A University of Cambridge-led study identifies the protein interferon gamma (IFN- γ ) as a potential biomarker for Long COVID fatigue and highlights an immunological